python写用户登录程序（继续更新中）第四讲（3）

def login(username,password):
"""
login my system  ---elcome to my sys!
:param username:
:param password:
:return:
"""
with open("log","r") as f:
for line in f:
line = line.strip()
line_l = line.split(":") #分割完会写在一个列表里面
if line_l[0] == username and line_l[1]:
return True
return False
#前提文件名为log的文件
def register(username,password):
"""
注册用户
:param username:用户名
:param password: 密码
:return: 注册成功
"""
with open("log","a") as f:
temp = "\n" + username + ":" + password
f.write(temp)
return True

def user_exsit(username):
"""
检测用户是否存在
:param username:要检测的用户名
:param password: 密码
:return: 用户已经存在
"""
with open("log","r") as f:
for line in f:
line= line.strip()
line_li = line.split(":")
if line_li[0] == username:
return True
return False
def main():
print("欢迎登陆我系统")
inp = input("1:登陆，2：注册")
user = input("please username:")
passwd = input("please password:")
if inp == "1":
if_login = login(user,passwd)
if if_login:
print("登陆成功")
else:
print("登陆失败")
elif inp == "2":
is_exsit = user_exsit(user)
if is_exsit:
print("用户名已经注册")
else:
result = register(user,passwd)
if result:
print("注册成功")
else:
print("注册失败")
main()